Giant spin–phonon bottleneck effects in evaporable vanadyl-based molecules with long spin coherence. Issue 42 (3rd August 2016)

• Record Type: Journal Article
• Authors: Tesi, L.; Lunghi, A.; Atzori, M.; Lucaccini, E.; Sorace, L.; Totti, F.; Sessoli, R.
• Is Part Of: Dalton transactions. Volume 45:Issue 42(2016)
• Page Start: 16635
• Page End: 16643
• Publication Date: 2016-08-03
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c6dt02559e
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : The smaller the ligand the slower the low temperature magnetization dynamics of the crystals of vanadyl complexes. Abstract : Vanadium(iv ) complexes have recently shown record quantum spin coherence times that in several circumstances are limited by spin–lattice relaxation. The role of the environment and vibronic properties in the low temperature dynamics is here investigated by a comparative study of the magnetization dynamics as a function of crystallite size and the steric hindrance of the β-diketonate ligands in VO(acac)2 (1 ), VO(dpm)2 (2 ) and VO(dbm)2 (3 ) evaporable complexes (acac − = acetylacetonate, dpm − = dipivaloylmethanate, and dbm − = dibenzoylmethanate). A pronounced crystallite size dependence of the relaxation time is observed at unusually high temperatures (up to 40 K), which is associated with a giant spin–phonon bottleneck effect. We model this behaviour by an ad hoc force field approach derived from density functional theory calculations, which evidences a correlation of the intensity of the phenomenon with ligand dimensions and the unit cell size.